This invention relates generally to the exercise art, and more particularly to a novel combined apparatus for exercising primarily either the hamstring or quadricep muscle groups of a user.
There have been weight resistance exercise machines able to exercise the hamstring and quadricep muscle groups of a user. However, such prior machines have commonly incorporated separate stations or submechanisms suited to individually exercise these two important muscle groups. For example, a chair and fixed pivot bar arrangement has been provided for performing leg extension exercises which develop the muscles in the quadricep group. A user seated in the chair engages the pivot bar with his lower leg and straightens the leg upwardly to a horizontal condition against the force of the machine. A separate thigh pad and pivot bar arrangement is then used for performing leg curl exercises which develop the hamstring muscles. The user stands before a pair of thigh pads and bends his lower leg backwardly to a horizontal condition.
Machines having separate stations for exercising the quadriceps and hamstrings not only take up an inordinate amount of space, but are also rather expensive to manufacture. These factors become critical in machines designed for use in the the home because the average home user has only a limited amount of space and money which he is willing to allocate to an exercise machine. The characteristics of machines having separate stations thus virtually preclude use of such machines in most homes.
A further limitation of prior machines having separate leg extension and leg curl stations is an inability to adjust the chair arrangements thereof to accommodate users having different femur lengths. It is therefore possible for a user having an unusually long or short femur to be positioned such that the axis of the pivot bar is spaced a substantial distance from the joint axis of the user's knee. This nonaligned condition of the machine and joint axes causes the machine arm and the user's leg to trace different arcs during an exercise. The roller at the end of the arm then rides up and down the leg, producing different conditions of leverage between the leg and the machine arm. Since the effective resistance to movement of the machine arm is dependent on the leverage condition between the leg and the arm the resistance felt by the user will also undesirably vary during the course of the exercise. Additionally, the roller can sometimes roll downwardly off the foot of the user releasing the pivot bar and possibly causing injury.
Some exercise machines have brought two stations together about a single bench for the purpose of performing leg extension and leg curl exercises. In machines of this type, two arms are connected perpendicularly for pivotal movement about a single fixed axis at the end of the bench. One of the pivot arms initially extends downwardly from the fixed axis while the other extends horizontally therefrom. Leg extension exercises are performed by a user sitting at the end of the bench and straightening his leg to raise the downwardly extending bar to a horizontal condition. Leg curl exercises are performed by the user lying face down on the bench and bending the lower leg upwardly to raise the horizontal arm to a vertical condition.
Machines of this second type are also rather bulky due to the two perpendicular pivot arms and the accompanying bench. In use, the bench is directed outwardly from the remainder of the exercise machine, with the perpendicular arms mounted to the outer end thereof. This configuration therefore aggravates the bulkiness of the assembled machine. There is also no assurance that the machine axis in this case will correspond to the joint axis of the user's knee because the joint axis is dependent entirely on the positioning of the user on the bench. Furthermore, the machine provides no back support for the user in a sitting position and requires the user to assume an awkward face down position for leg curls.
Therefore, it is desirable to provide an apparatus for performing leg extension and leg curl exercises at a single station of an exercise machine while maintaining the machine axis of the engaging pivot arm substantially at the joint axis of the user's knee.